KR20180117079A - Organic optoelectronic device and method of manufacturing same - Google Patents

Abstract

The present invention provides an organic optoelectronic device and a manufacturing method thereof. The organic optoelectronic device comprises: a first electrode; a second electrode disposed to face the first electrode; and an active layer with one or more layers disposed between the first and second electrodes. At least one of the first and second electrodes includes a metal layer exhibiting surface plasmon resonance including metal nanoparticles disposed at uniform spaces on a surface in contact with the active layer. The organic optoelectronic device can represent improved device efficiency by a surface plasmon resonance phenomenon of the metal nanoparticles by forming the metal layer including the metal nanoparticles between the electrodes and the active layer.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic electroluminescence device,

The present invention relates to an organic optoelectronic device and a method of manufacturing the same.

Organic solar cells included in organic optoelectronic devices can be manufactured by a simple process, are environmentally friendly, have a semi-permanent lifetime, and thus, they are attracting attention as a future energy source. Another organic electroluminescent device, which is an organic electroluminescent device, is not only easy to fabricate, but also has excellent luminous efficiency and can be used as a light source for an environmentally friendly lighting device.

In order to increase the efficiency of such a next generation organic optoelectronic device, various researches are being carried out such as synthesis of new materials, development of device manufacturing technology, and modification of device structure.

A typical method for increasing the device efficiency in an organic solar cell is to improve the solar light absorbing ability of the photoactive layer in the device. In order to increase the solar absorption, the thickness of the photoactive layer should be increased, which increases the internal resistance of the device.

For high efficiency organic light emitting devices, the formation of radiative excitons and the emission of light by decay of these electron-hole pairs are important factors. However, about 50% of the light formed by the electron-hole pairs does not emit light to the outside, and is trapped in the device or lost due to reabsorption. Therefore, various methods are currently being studied to solve these problems.

One embodiment of the present invention is to provide an organic optoelectronic device exhibiting improved device efficiency using surface plasmon resonance phenomenon.

Another embodiment of the present invention provides a method of manufacturing the organic optoelectronic device.

An organic optoelectronic device according to an embodiment of the present invention includes a first electrode, a second electrode arranged to face the first electrode, and at least one active layer positioned between the first electrode and the second electrode, And at least one of the first electrode and the second electrode includes a metal layer including metal nanoparticles arranged at a uniform interval on a surface side in contact with the active layer to exhibit surface plasmon resonance.

The metal nanoparticles may be uniformly formed at intervals of 5 to 100 nm, and preferably the metal nanoparticles may be uniformly formed at intervals of 5 to 30 nm.

The metal nanoparticles may have an average particle diameter of 5 to 100 nm, and preferably have an average particle diameter of 10 to 30 nm.

The metal nanoparticles may have a dot or ring structure.

The metal nanoparticles may have a ring structure having an outer diameter and an inner diameter ratio of 1.5: 1 to 3: 1.

The metal nanoparticles may be selected from the group consisting of gold, silver, copper, alloys thereof, and mixtures thereof.

The organic optoelectronic device may be an organic solar cell or an organic light emitting device.

According to another embodiment of the present invention, there is provided a method of manufacturing an organic optoelectronic device, comprising: preparing a composition for forming a metal layer by mixing a metal precursor and a block copolymer; Providing a metal layer by applying the composition for forming a metal layer on at least one surface of the first electrode and the second electrode and reducing the metal precursor to form metal nanoparticles; And sequentially stacking the first electrode, the one or more active layers, and the second electrode.

Wherein the metal precursor is selected from the group consisting of hydrochloric acid, chloride, nitrate, sulfate, acetate, hydrates thereof, and mixtures thereof comprising metals selected from the group consisting of gold, silver, copper, alloys thereof, .

The metal precursor may be selected from the group consisting of hydrogen tetrachloroaurate (HAuCl ₄ ), cupric chloride (CuCl ₂ ), silver nitrate (AgNO ₃ ), copper sulfate (CuSO ₄ ), copper nitrate (Cu (NO ₃ ) ₂ ) (CH ₃ COO)), hydrates thereof, and mixtures thereof.

The metal precursor may be used in an amount of 0.1 to 1 equivalent.

The block copolymer may have a number average molecular weight (Mn) of 10 to 1000 KDa.

The block copolymer may be at least one selected from the group consisting of polystyrene-polyvinylpyridine block copolymers (PS- b- P2VP, PS- b- P4VP), polystyrene-polyethylene oxide (PS- b- PEO), polyisoprene- P2VP, PI-b-P4VP), and mixtures thereof.

The block copolymer may be used in a concentration of 0.3 to 1% by weight.

The reduction process for the metal precursor may be performed by plasma treatment of the metal precursor or heat treatment at 300 to 500 ° C.

The plasma treatment may be performed using a hydrogen plasma, an argon plasma, or an oxygen plasma.

The heat treatment may be carried out under a hydrogen, nitrogen or argon atmosphere.

Other details of the embodiments of the present invention are included in the following detailed description.

The organic optoelectronic device can exhibit improved device efficiency by inducing surface plasmon resonance phenomena of metal nanoparticles by forming a metal layer including metal nanoparticles between the electrode and the active layer.

In addition, in the method of manufacturing the organic optoelectronic device, metal nanoparticles are directly loaded on a block copolymer by using a metal precursor in forming a metal layer, and the size, spacing, and size of metal nanoparticles formed by the molecular weight and concentration of the block copolymer By controlling the structure, metal nanoparticles having a uniform size at uniform intervals can be easily formed in the metal layer.

1 is a perspective view illustrating an organic solar cell according to an embodiment of the present invention.
2 is a perspective view illustrating an organic light emitting device according to an embodiment of the present invention.
3 is a process diagram schematically showing a manufacturing process of an organic optoelectronic device according to an embodiment of the present invention.
FIG. 4A is an atomic force microscopy (AFM) image of a coating film of a composition for forming a metal layer formed on an ITO (indium tin oxide) electrode before removal of a block copolymer by plasma treatment in Example 1, FIGS. 4C and 4D are atomic micrographs of metal nanoparticles formed on each metal layer formed on the ITO electrode after removal of the block copolymer in the organic solar cell manufacturing processes according to Examples 1 to 3, respectively. FIG.
FIG. 5A is a graph showing the results of observation of ultraviolet-visible light absorption spectra of metal nanoparticles in the metal layer of the organic solar cell prepared in Examples 1 to 3. FIG. The optical properties of the metal nanoparticles in the metal layer of the cell are determined by a three-dimensional finite difference time domain (FDTD) method. 5C is a graph (λ = 567 nm) of a normalized field distribution (| E |) of gold nanoparticles according to Example 2. FIG.
6 is a graph showing the results of photocatalytic activity of poly (2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylene vinylene) in the organic luminescent devices prepared in Examples 5 to 7 and Comparative Example 2 Lt; / RTI > layer.
FIG. 7A is a graph showing the results of observing the current density-voltage characteristics of the organic solar cells manufactured in Examples 1 to 3 and Comparative Example 1. FIG. 7B is a graph showing the results of observation of the current density-voltage characteristics of the organic solar cells manufactured in Examples 1 to 3 and Comparative Example 1. FIG. And the external quantum efficiency (EQE) of the battery according to the wavelength.
FIG. 8A is a graph of current density-voltage of the organic light emitting device manufactured in Examples 5 to 7 and Comparative Example 2, FIG. 8B is a graph of luminance-voltage of the organic light emitting device manufactured in Examples 5 to 7 and Comparative Example 2 And FIG. 8C is a graph of luminescence efficiency-current density characteristics of the organic light emitting devices manufactured in Examples 5 to 7 and Comparative Example 2.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

The present invention relates to an organic optoelectronic device including an organic solar cell or an organic light emitting device, and a metal layer containing metal nanoparticles having a uniform particle size at uniform intervals using a block copolymer to introduce metal nanoparticles Is characterized in that the element efficiency is improved by the surface plasmon resonance phenomenon.

That is, an organic optoelectronic device according to an embodiment of the present invention includes a first electrode, a second electrode arranged to face the first electrode, and at least one active layer positioned between the first electrode and the second electrode And at least one of the first electrode and the second electrode includes a metal layer including metal nanoparticles arranged at a uniform interval on a surface side in contact with the active layer to exhibit surface plasmon resonance.

The metal nanoparticles in the metal layer generate a surface plasmon resonance phenomenon having a magnitude larger than that of incident light due to interaction between free electrons in the particle and light or electromagnetic waves. Therefore, pure metal or alloy having free electrons can be used as the metal nanoparticles. Specifically, a material selected from the group consisting of gold, silver, copper, an alloy thereof, and a mixture thereof may be used, and it is preferable to use gold, copper, or gold-copper alloy from the viewpoint of improving device efficiency.

The metal nanoparticles are formed by directly loading metal nanoparticles into a block copolymer using a metal precursor, then removing the block copolymer and reducing the metal precursor. Therefore, by controlling the molecular weight and concentration of the block copolymer, the spacing, size and structure of the metal nanoparticles formed in the metal layer can be controlled.

Considering the effect of improving the device efficiency, it is preferable that the metal nanoparticles are formed at uniform intervals of 5 to 100 nm, preferably 5 to 30 nm. If the interval of the metal nanoparticles is less than 5 nm, the transmittance may decrease. If the interval exceeds 100 nm, the surface plasmon resonance effect is not expected.

The metal nanoparticles preferably have an average particle diameter of 5 to 100 nm, preferably 10 to 30 nm. When the average particle diameter of the metal nanoparticles is less than 5 nm, there is a concern that it is difficult to expect a plasmon effect in a desired wavelength region due to a blue shift phenomenon. When the average particle diameter is more than 100 nm, the transmittance may be affected.

In addition, the metal nanoparticles may have a dot or ring structure, and the metal nanoparticles preferably have a ring structure in terms of device efficiency enhancement.

Specifically, when the metal nanoparticles have a ring structure, the ratio of the outer diameter to the inner diameter of the ring is preferably 1.5: 1 to 3: 1, more preferably 1.5: 1 to 2: 1. If the ratio of the outer diameter to the inner diameter is less than 1.5: 1, it may be difficult to expect the surface plasmon effect of the ring structure. If the ratio is 3: 1 or more, there is a concern that the plasmon effect due to the ring structure may not be expected.

The metal layer including the metal nanoparticles may be formed on the first electrode, the second electrode, or both electrodes of the organic optoelectronic device. Preferably, the metal layer is formed on the surface of the electrode, It is good to have less influence on organic matter.

The first electrode, the second electrode, and the active layer can be used without any particular limitation as long as they are used in an organic optoelectronic device.

The organic optoelectronic device according to the present invention includes an organic solar cell and an organic light emitting device.

When the organic optoelectronic device according to the present invention is an organic solar cell, the organic solar cell has a thin film structure in which a first electrode, an active layer, and a second electrode are sequentially laminated, And a metal layer including metal nanoparticles between the second electrode and the active layer or both.

The first electrode and the second electrode are divided into a positive electrode and a negative electrode according to functions thereof. A transparent electrode of indium tin oxide (ITO) is formed on the anode, and a transparent electrode of aluminum (Al) May be used. At this time, a metal having a low work function such as silver (Ag) or copper (Cu) may be used instead of the aluminum (Al). The active layer may include at least one photoactive layer and the photoactive layer may have a single layer structure having a bulk heterojunction structure in which a hole acceptor and an electron acceptor are mixed, Layer structure including a receptor and an electron acceptor as separate layers. The photoactive layer may include a conjugated polymer and a fullerene derivative serving as an electron acceptor. The conjugated polymer may be selected from the group consisting of polythiophene, polycarbazole, polyfluorene, polysilyl, polyphenylene and derivatives thereof, Concretely, poly (3-hexylthiophene: P3HT), poly (2,6- (4,4-bis- (2-ethylhexyl) -4H-cyclopenta 4-b '] dithiophene) -tallow-4,7- (2,1,3-benzothiadiazole)], PCDTBT (poly [N-9 "-hepta-decanyl-2,7- - (4 ', 7'-di-2-thienyl-2', 1 ', 3'-benzothiadiazole)], PFDTBT (poly (2,7- (2-methoxy-5- (4 ', 7'-di-2-thienyl-2', 1 ', 3'- benzothiadiazole) 2'-ethyl-hexyloxy) -1,4-phenylene vinylene], poly [2-methoxy-5- (3,7-dimethyloctyloxy) -1,4-phenylene vinylene] PCBM ([6,6] -phenyl-C61 butyric acid methyl ester) may be used as the fullerene derivative. The active layer may further include a buffer layer, and the buffer layer may be formed of poly (3,4-ethylenedioxylenethiophene) (polystyrene sulfonic acid (PEDOT: PSS) Or MoO _3. The metal layer is the same as described above.

1 is a perspective view illustrating an organic solar cell having a metal layer formed between an anode and an active layer according to an embodiment of the present invention. However, FIG. 1 is only one example for embodying the present invention, and the organic solar cell according to the present invention is not limited to FIG. 1, an organic solar battery 10 according to the present invention includes a substrate 11; A first electrode (anode) 12; A metal layer 13; An active layer including a buffer layer 14a and a photoactive layer 14b; And a second electrode (cathode) 15 are sequentially stacked.

When the organic electroluminescent device according to the present invention is an organic light emitting device, the organic light emitting device has a structure in which a first electrode, an active layer, and a second electrode are sequentially stacked, and between the first electrode and the active layer, And a metal layer including metal nanoparticles between the second electrode and the active layer or both. The first electrode and the second electrode are divided into an anode and a cathode according to their functions. A transparent electrode of indium tin oxide (ITO) is formed on the anode, and a transparent electrode of aluminum (Al) May be used. At this time, a metal having a low work function such as silver (Ag) or copper (Cu) may be used instead of the aluminum (Al). Further, in order to facilitate the injection of electrons, a barium layer may be further formed prior to the formation of the aluminum (Al) electrode, and instead of the barium having a low work function, Cs ₂ CO ₃ , TiO _X (1.5? _X ? 3), ZnO, or the like may be used. The active layer may have a multi-layer structure including at least two organic active layers selected from a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer, but is not limited thereto and may have a single layer structure. The organic active layer may be a poly (2-methoxy-5- (2-ethyl-hexyloxy) -1,4-phenylenevinylene ) -1,4-phenylene vinylene (MEH-PPV). The active layer may further include a buffer layer, and the buffer layer may include a poly (3,4-ethylenedioxyanthiophene: Poly (3,4-ethylenedioxylenethiophene): polystyrene sulfonic acid (PEDOT: PSS) or MoO _3. The metal layer is the same as described above.

2 is a perspective view illustrating an organic light emitting device having a metal layer formed between an anode and an active layer according to an embodiment of the present invention. However, FIG. 2 is only one example for embodying the present invention, and the organic light emitting device according to the present invention is not limited to FIG. 2, the organic light emitting device 20 according to the present invention includes a substrate 21; A first electrode (anode 22); A metal layer 23; An active layer including a buffer layer 24a and an organic active layer 24b; And the cathode 25 may be sequentially stacked.

The organic optoelectronic device according to one embodiment of the present invention having the above structure comprises: preparing a composition for forming a metal layer by mixing a metal precursor and a block copolymer; Providing a metal layer by applying the composition for forming a metal layer on at least one surface of the first electrode and the second electrode and reducing the metal precursor to form metal nanoparticles; And a step of sequentially laminating the first electrode, the one or more active layers and the second electrode.

3 is a process diagram schematically showing a manufacturing process of an organic optoelectronic device according to an embodiment of the present invention. Referring to FIG. 3, each step will be described in detail.

First, a metal precursor and a block copolymer are mixed to prepare a composition for forming a metal layer (Step 1).

Specifically, the composition for forming a metal layer may be prepared by dissolving a metal precursor and a block copolymer in a solvent.

Wherein the metal precursor is selected from the group consisting of hydrochloric acid, chloride, nitrate, sulfate, acetate, hydrates thereof, and mixtures thereof, comprising a metal selected from the group consisting of gold, silver, copper, alloys thereof, You can use what is selected. More specifically, it was found that hydrogen tetrachloroaurate (HAuCl ₄ ), cupric chloride (CuCl ₂ ), silver nitrate (AgNO ₃ ), copper sulfate (CuSO ₄ ), copper nitrate (Cu (NO ₃ ) ₂ ) CH ₃ COO)), hydrates thereof, and mixtures thereof.

The metal precursor is preferably used in an amount of 0.1 to 1 equivalent, preferably 0.3 to 0.8 equivalent, in consideration of the content of the metal nanoparticles contained in the final metal layer. When the metal precursor is used in the above range, the amount of the finally formed metal nanoparticles can be sufficiently obtained and uniform metal nanoparticles can be obtained.

Wherein the block copolymer is polystyrene-polyvinylpyridine block copolymer (polystyrene- block- poly (2-vinylpyridine : PS- b -P2VP), polystyrene- block -poly (4-vinylpyridine: PS- b -P4VP) , etc.), polystyrene-polyethylene oxide (polystyrene- block -poly (ethyleneoxide: PS- b -PEO), polyisoprene-polyvinylpyridine (polyisoprene- block- poly (2-vinylpyridine : PI- b -P2VP), polyisoprene- block -poly ( 4-vinylpyridine: PI- b- P4VP)), and mixtures thereof.

The block copolymer can control the structure, size, and spacing of the metal nanoparticles finally prepared according to the molecular weight and amount of the block copolymer. Therefore, it is preferable to use a block copolymer having a number average molecular weight (Mn) of 10 to 1000 KDa. The block copolymer having the number average molecular weight in the above range is easy to produce metal nanoparticles of various ring structures, for example, and can provide a uniform polymer mold.

The block copolymer is preferably used in a concentration of 0.3 to 1% by weight. When the amount of the block copolymer is in the above range, a sufficient surface plasmon effect can be obtained and at the same time, the transparency of the active layer can be sufficiently secured.

Specifically, when the metal nanoparticles in the final metal layer are formed at a uniform particle interval of 5 to 100 nm and have a dot structure, the metal nanoparticles may be added in an amount of 0.3 to 1 wt% , And when the metal nanoparticles have a ring structure together with the particle interval as described above, a block copolymer having a number average molecular weight of 20 to 800 KDa is used in a concentration of 0.3 to 0.8% by weight .

Also, when the metal nanoparticles have a ring structure, 2-methylbenzylalcohol, benzylalcohol, 4-hydroxybenzene-azo-2-benzoic acid, azo-2-benzoic acid) and mixtures thereof may be further used in an amount of 0.1 to 0.8% by weight. As the solvent, it is preferable to use a selective solvent for a block copolymer such as toluene, xylene, m-xylene, p-xylene, trifluorotoluene or tetrahydrofuran.

For example, when a block copolymer of polystyrene-polyvinylpyridine is dissolved in a solvent, a polyvinylpyridine core is formed, and spherical micelles surrounding the polystyrene are formed around the core. These spherical micelles are then applied on electrodes to form micelles filled with a semi-hexagonal structure, and the metal nanoparticles are arranged using these micelles as a template.

Next, the metal layer forming composition is coated on at least one surface of the first electrode and the second electrode, and the metal precursor is reduced to form a metal layer (step 2).

When a metal layer is formed on the ITO transparent electrode, the ITO transparent electrode can be pretreated. Specifically, ITO may be ultrasonically washed with water, acetone, isopropanol, or the like, or ultraviolet (UV) treatment may be performed.

The method of applying the composition for forming a metal layer can be carried out by a conventional method, and specifically, it can be carried out by a spin coating method or the like.

It is preferable that the composition for metal layer formation is spin-coated at a speed of 1000 to 5000 rpm for 30 to 60 seconds.

Then, the block copolymer contained in the coated metal layer forming composition is removed. The block copolymer may be removed by plasma treatment or heat treatment at 300 to 500 ° C. During this process, metal ions of the metal precursor are reduced to metal nanoparticles. In this case, the plasma treatment may be performed by a hydrogen plasma, an argon plasma, or an oxygen plasma treatment. In order to prevent the oxidation of the metal nanoparticles formed in the metal layer, the heat treatment may be performed in an inert atmosphere, . ≪ / RTI >

Then, the first electrode, the active layer, and the second electrode are sequentially laminated to produce an organic optoelectronic device (Step 3).

The first electrode, the one or more active layers, and the second electrode are as described above, and the production method thereof can be carried out according to a conventional method. Therefore, a detailed description thereof will be omitted herein.

The method of manufacturing an organic optoelectronic device according to an embodiment of the present invention is characterized in that a metal precursor is directly loaded on a block copolymer for introduction of metal nanoparticles in the metal layer formation and is formed by the molecular weight and concentration of the used block copolymer By adjusting the size, spacing and structure of the metal nanoparticles to be formed, metal nanoparticles having a uniform size at uniform intervals can be easily formed in the metal layer as compared with the method of forming metal nanoparticles by the conventional casting method.

The organic optoelectronic device manufactured by the above method has a metal layer including metal nanoparticles between the electrode and the active layer so that free electrons in the metal nanoparticles are improved by surface plasmon resonance generated through resonance with light The device efficiency can be shown. Specifically, in the organic solar cell including the metal layer according to the present invention, the absorption of the photoactive layer is increased due to the surface plasmon phenomenon, and the recombination speed of the electron-hole pairs is accelerated due to the plasmon resonance effect in the organic light- Efficiency can be obtained.

Hereinafter, specific embodiments of the present invention will be described. However, the embodiments described below are only intended to illustrate or explain the present invention, and thus the present invention should not be limited thereto.

[Manufacturing Example]

Preparation Example 1: Preparation of composition for metal layer formation using block copolymer

Polystyrene-polyvinylpyridine block copolymer (PS- b- P2V, Mn ^PS = 133 kg / mol, Mn ^P2VP = 132 kg / mol, Mw / Mn = 1.05) having a molecular weight of 265 KDa was dissolved in toluene and tetrahydrofuran THF) at a concentration of 0.4 wt%, 0.8 equivalent of HAuCl ₄ was added to the solution, and the mixture was stirred for 12 hours to prepare a composition for forming a metal layer.

Production Example 2: Preparation of composition for metal layer formation using block copolymer

A composition for forming a metal layer was prepared in the same manner as in Preparation Example 1, except that cupric chloride (CuCl ₂ ) was used instead of tetrachloromethane (HAuCl ₄ ).

Production Example 3: Preparation of gold-copper alloy nanoparticles using block copolymer

A solution prepared by dissolving a polystyrene-polyvinylpyridine block copolymer (PS- b- P2VP) having a molecular weight of 265 KDa in a mixed solution of toluene and tetrahydrofuran (THF) at a concentration of 0.4 wt% (HAuCl ₄ ) was added thereto, and the mixture was stirred for 12 hours. 0.4 eq. Cupric chloride (CuCl ₂ ) was further added thereto and stirred for 12 hours or longer to prepare a composition for forming a metal layer.

Production Example 4: Preparation of silver nanoparticles using block copolymer

A composition for forming a metal layer was prepared in the same manner as in Preparation Example 1, except that silver nitrate (AgNO ₃ ) was used instead of tetrachloromethane (HAuCl ₄ ).

Examples 1 to 4: Preparation of organic solar cell

ITO (indium tin oxide) was washed, ultrasonically cleaned in the order of water, acetone and isopropanol, and the cleaned ITO substrate was treated with ultraviolet (UV) treatment for about 10 minutes. The prepared substrate was spin coated with the metal layer forming compositions prepared in Production Examples 1 to 4 at 4000 rpm for 40 seconds and hydrogen plasma treatment was performed to remove the block copolymer contained in the metal layer forming composition to form a metal layer.

Poly (3,4-ethylenedioxylenethiophene): polystyrene sulfonic acid (PEDOT: PSS) was spin-coated on the formed metal layer at 4000 rpm for 40 seconds and then dried at 140 ° C for 10 minutes 2% by weight of poly (3-hexylthiophene): [6,6] -phenyl-C61 butyric acid methyl ester (PEG) was added to the buffer layer in a nitrogen atmosphere. (P3HT: PCBM) bulk heterojunction system) was spin-coated at 700 rpm for 60 seconds to form a photoactive layer. Aluminum (Al) was deposited on the photoactive layer to a thickness of 100 nm by thermal evaporation to form aluminum (Al) electrode, an organic solar cell having the structure of ITO electrode / metal layer / buffer layer / photoactive layer / Al electrode was manufactured as shown in FIG.

Examples 5 to 8: Preparation of organic light emitting device

ITO was cleaned with detergent, followed by ultrasonic cleaning in the order of water, acetone and isopropanol, and the cleaned ITO substrate was subjected to ultraviolet (UV) treatment for about 10 minutes to prepare a substrate. The prepared substrate was spin-coated with the metal layer forming compositions prepared in Preparation Examples 1 to 4 at 4000 rpm for 40 seconds and subjected to nitrogen plasma treatment to remove the block copolymer contained in the metal layer forming composition to form a metal layer.

The formed metal layer was spin coated with PEDOT (PSS) at 4000 rpm for 40 seconds and then dried at 140 DEG C for 10 minutes to form a buffer layer. (2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylenevinylene) (poly (2 -methoxy-5- (2-ethyl-hexyloxy) -1,4-phenylene vinylene: MEH-PPV) was spin-coated at 1500 rpm for 60 seconds to form an organic active layer. Thermal evaporation (Al) was deposited on the ITO electrode / metal layer / buffer layer / active layer / BA / Al electrode as shown in FIG. 2 by depositing barium (Ba) Lt; / RTI > was fabricated.

Comparative Example 1

An organic solar cell was manufactured in the same manner as in Example 1 except that a metal layer was not formed on the ITO electrode.

Comparative Example 2

An organic light emitting device was fabricated in the same manner as in Example 5 except that a metal layer was not formed on the ITO electrode.

Test Example 1: Observation of a metal layer formed on an organic optoelectronic device

The metal layer formed on the ITO electrode during the organic solar cell manufacturing process according to Examples 1 to 3 was observed by atomic force microscopy (AFM). The results are shown in Figs. 4A to 4D, respectively.

FIG. 4A is an atomic force microscope image of a coating film of a composition for forming a metal layer formed on an ITO (indium-tin oxide) electrode before removal of a block copolymer by plasma treatment in Example 1. FIGS. 4B, 4C, 1 to 3, the metal nanoparticles in each metal layer formed on the ITO electrode after the removal of the block copolymer are observed under an atomic force microscope.

As shown in FIG. 4A, the micelles of PS- b- P2VP block copolymer containing a gold precursor can be observed in the coating film of the composition for forming a metal layer.

4B to 4D, in the metal layers of Examples 1 to 3 formed using the block copolymer having a number average molecular weight of 265K after the plasma treatment of the coating film of the composition for forming a metal layer, each of the metal nanoparticles Were formed with a very uniform distribution with a diameter of about 25 nm and an interval of 100 nm.

Test Example 2: Observation of surface plasmon resonance of organic optoelectronic devices

The organic solar cells prepared in Examples 1 to 3 were prepared using the UV-Vis absorption spectroscopy method and the three-dimensional finite difference time domain method (FDTD method) Surface plasmon resonance phenomenon was observed. The results are shown in Figs. 5A to 5C.

FIG. 5A is a graph showing the results of observation of ultraviolet-visible light absorption spectra of metal nanoparticles in the metal layer of the organic solar cell prepared in Examples 1 to 3. FIG. The optical properties of the metal nanoparticles in the metal layer of the cell are determined by a theoretical value using the FDTD method, and are a normalized extinction simulation spectrum.

5A, surface plasmon resonance of the gold nanoparticles contained in the metal layer of the organic solar cell of Example 1 occurred at 540 nm, and the surface plasmon resonance of the copper nanoparticles contained in the metal layer of the organic solar cell of Example 2 The plasmon resonance occurred around 600 nm. The plasmon resonance of the gold-copper alloy nanoparticles in the metal layer of the organic solar cell of Example 3 occurred at an intermediate position between gold and copper, and the approximate range was 550 to 600 nm. This migration of the plasmon resonance peak indicates that the alloy has both gold and copper properties.

As can be seen from FIG. 5B, the plasmon resonance peaks of the gold, copper and gold-copper nanoparticles contained in the metal layer of the organic solar cell of Examples 1 to 3 obtained from the theoretical simulation were 567 nm, 582 nm and 572 nm, It can be seen that the measured results of the ultraviolet-visible light absorption graph of the metal nanoparticles in FIG. 4a agree well with each other.

5C is a graph (λ = 567 nm) of a normalized field distribution (| E |) of gold nanoparticles according to Example 2. FIG.

Additionally, semiconducting polymers such as poly (2-methoxy-5- (2-ethylhexyloxy) -1,4-phenylenevinylene (poly In order to observe the photoluminescence effect of the metal nanoparticles on hexyloxy-1, 4-phenylene vinylene (MEH-PPV), the photoluminescence spectroscopy was used to determine the organic The surface plasmon resonance phenomenon was observed for the light emitting device. The results are shown in Fig.

6 is a fluorescence spectrum of a photoactive layer containing MEH-PPV in the organic light-emitting device manufactured in Examples 5 to 7 and Comparative Example 2. FIG.

As shown in FIG. 6, the fluorescence intensities of the photoactive layer in the organic light emitting devices of Examples 5 to 7, in which the metal layer containing metal nanoparticles were introduced, were relatively increased Respectively. This is due to the increased absorption of light incident by the increased local electromagnetic due to the plasmon resonance of the surface metal nanoparticles.

Test Example 3: Evaluation of characteristics of organic optoelectronic devices

Short-circuit current (IEC) was measured for the organic solar cells prepared in Examples 1 to 3 using a solar simulator (equipped with Keithley 2635A source measurement) and a PV measurement QE system using a xenon lamp. J _SC ), current density (η), open circuit voltage ( V _OC ), and fill factor (FF). The results are shown in Table 1 and Figs. 7A and 7B, respectively.

FIG. 7A is a graph showing the results of observing the current density-voltage characteristics of the organic solar cells manufactured in Examples 1 to 3 and Comparative Example 1. FIG. 7B is a graph showing the results of observation of the current density-voltage characteristics of the organic solar cells manufactured in Examples 1 to 3 and Comparative Example 1. FIG. (EQE), which is a current conversion efficiency of an incident photon of a battery, according to a wavelength.

J _sc [mAcm ^-2 ] V _oc [V] FF [%] η [%] Theoretical values of J _sc
[mAcm ^-2 ] Comparative Example 1 8.08 0.60 0.60 2.90 8.18 Example 1 8.50 0.58 0.60 2.98 8.69 Example 2 9.60 0.58 0.58 3.22 9.23 Example 3 9.37 0.58 0.61 3.35 9.29

As can be seen from Table 1 and FIGS. 7A and 7B, the organic solar cells of Examples 1 to 3 including a metal layer showed a current density increased by 5 to 20% as compared with the organic solar cell of Comparative Example 1 which did not include a metal layer, This increased current density can be confirmed by the fact that the amount of light absorbed at the wavelength at which the surface plasmon resonance is increased is influenced by the surface plasmon resonance of the metal nanoparticles introduced into the organic solar cell.

The characteristics of the organic light emitting devices prepared in Examples 5 to 7 were evaluated (measured using Keithley 2400 source measurement equipped with Minolta CS 2000). The results are shown in Table 2 and Figs. 8A and 8C, respectively.

FIG. 8A is a graph of current density-voltage of the organic light emitting device manufactured in Examples 5 to 7 and Comparative Example 2, FIG. 8B is a graph of luminance-voltage of the organic light emitting device manufactured in Examples 5 to 7 and Comparative Example 2 And FIG. 8C is a graph of luminescence efficiency-current density characteristics of the organic light emitting devices manufactured in Examples 5 to 7 and Comparative Example 2. FIG.

Maximum luminance
[cd / m ² ] (at that voltage) Maximum luminous efficiency
[cd / A] (at that voltage) Turn-on voltage
(turn on voltage) [V] Comparative Example 2 16932 (5.6V) 1.40 (4.2V) 2.2 Example 5 22268 (6.2V) 1.61 (5.4V) 2.2 Example 6 22636 (6.4V) 1.74 (5.8V) 2.2 Example 7 20973 (6.4V) 1.57 (5.4 V) 2.2

As can be seen from Table 2 and Figs. 8A to 8C, the organic light emitting devices of Examples 5 to 7 including the metal layer exhibited higher luminance than the organic light emitting device of Comparative Example 2 which did not include the metal layer, and 12 to 24% And improved luminous efficiency. This high brightness and increased luminescence efficiency can be attributed to the fact that the metal nanoparticles and the surface plasmon in which the light resonance promoted the recombination of spinnable electron-hole pairs.

As described in the above description, the organic optoelectronic device of the present invention can increase the current density due to increased absorption due to the surface plasmon resonance phenomenon in a solar cell by introducing metal nanoparticles. In the light emitting device, The efficiency of the device can be improved by accelerating the recombination speed.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

10: Organic solar cell 20: Organic light emitting device
11, 21: substrate
12, 22: a first substrate
13, 23: metal layer
14a, 24a:
14b: photoactive layer 24b: organic active layer
15, 25: second electrode

Claims (9)

The first electrode,
A second electrode arranged to face the first electrode, and
And at least one active layer positioned between the first electrode and the second electrode,
Wherein at least one of the first electrode and the second electrode comprises a metal layer including metal nanoparticles arranged at a uniform interval on a surface side in contact with the active layer and exhibiting surface plasmon resonance,
Wherein the metal nanoparticles are selected from the group consisting of copper, a copper alloy, and a mixture containing copper.
The method according to claim 1,
Wherein the metal nanoparticles are uniformly formed at an interval of 5 to 100 nm.
The method according to claim 1,
Wherein the metal nanoparticles are uniformly formed at intervals of 5 to 30 nm.
The method according to claim 1,
Wherein the metal nanoparticles have an average particle diameter of 5 to 100 nm.
The method according to claim 1,
Wherein the metal nanoparticles have an average particle diameter of 10 to 30 nm.
The method according to claim 1,
Wherein the metal nanoparticles have a dot or ring structure.
The method according to claim 1,
Wherein the metal nanoparticles have a ring structure having an outer diameter and an inner diameter ratio of 1.5: 1 to 3: 1.
The method according to claim 1,
Wherein the metal nanoparticles are copper.
The method according to claim 1,
Wherein the organic optoelectronic device is an organic solar cell or an organic light emitting device.

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